<template>
    <div class="login_container">
        <div class="login_box">
            <!-- 头像区域 -->
            <div class="avatar_box">
                <img src="../assets/logo.png" alt="logo">
            </div>
            <!-- 表单区域 -->
            <el-form ref="loginFormRef" class="form_box"  :model="loginForm" :rules="loginFormRules">
                <!-- username -->
                <el-form-item prop="username">
                    <el-input  prefix-icon="el-icon-user-solid" v-model="loginForm.username"></el-input>
                </el-form-item>
                <!-- password -->
                <el-form-item prop="password">
                    <el-input show-password prefix-icon="el-icon-lock" v-model="loginForm.password"></el-input>
                </el-form-item>
                <!-- button -->
                <el-form-item class="btns">
                    <el-button type="primary" @click="login">登录</el-button>
                    <el-button type="info" @click="resetLoginForm">重置</el-button>
                </el-form-item>
            </el-form>
        </div>
    </div>
</template>

<script>
export default {
  data() {
    return {
      // 表单登录的数据对象
      loginForm: {
        username: 'admin',
        password: '123456'
      },
      // 表单验证规则对象
      loginFormRules: {
        // 用户名验证
        username: [
          { required: true, message: '请输入用户名', trigger: 'blur' },
          { min: 3, max: 5, message: '长度在 3 到 5 个字符', trigger: 'blur' }
        ],
        // 密码验证
        password: [
          { required: true, message: '请输入密码', trigger: 'blur' },
          { min: 6, max: 15, message: '长度在 6 到 15个字符', trigger: 'blur' }
        ]
      }
    }
  },
  methods: {
    resetLoginForm() {
      this.$refs.loginFormRef.resetFields()
    },
    login() {
      // 预验证
      this.$refs.loginFormRef.validate(async valid => {
        if (!valid) return false
        const { data: res } = await this.$http.post('login', this.loginForm)
        if (res.meta.status !== 200) return this.$message.error('用户名或者密码错误，请重新输入！！！')
        this.$message.success('登录成功')
        // 1.将登录成功之后的token，保存到客户端的sessionStorage
        // 1.1项目中除了登录之外的其他API接口，必须在登录之后才能访问
        // 1.2token只应在当前网站打开期间生效，所以token保存在sessionStorage中
        window.sessionStorage.setItem('token', res.data.token)
        // 2.通过编程式导航跳到后台主页，路由地址是home
        this.$router.push('/home')
      })
    }
  }
}
</script>

<style lang="less" scoped>
    // 登录主样式
    .login_container {
        background-color: #2b4b6b;
        height: 100%
    }
    // 登陆盒子
    .login_box {
        width: 450px;
        height: 300px;
        background-color: #fff;
        border-radius: 3px;
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);

        // logo
        .avatar_box {
            height: 130px;
            width: 130px;
            border: 1px solid #eee;
            border-radius: 50%;
            padding: 10px;
            box-shadow: 0 0 10px #000;
            position: absolute;
            left: 50%;
            transform: translate(-50%, -50%);
            background-color: #fff;
            img {
                width: 100%;
                height: 100%;
                border-radius: 50%;
                background-color: #ccc;
            }
        }
        // 按钮
        .btns {
            display: flex;
            justify-content: center;
        }
        // 输入框
        .form_box {
            position: absolute;
            bottom: 0;
            width: 100%;
            padding: 0 20px;
            box-sizing: border-box;
        }
    }
</style>
